PCDD/F emission characteristics in different waste incineration facilities and evaluation of 23478-PeCDF as I-TEQ indicator of PCDD/F in flue gases

The emission characteristics of PCDD/F from different waste incineration facilities in China, the correlations of different PCDD/F isomers with I-TEQ and the linear regression analysis of 23478-PeCDF with I-TEQ were reported in this article. Statistical analysis of the homologue patterns of PCDD/F in different incineration facilities will provide valuable information in environmental survey to find the contamination sources. PCDD/F congener patterns were almost constant among municipal and hazardous waste incineration facilities with only very small variations, but those patterns in medical waste incineration facilities were slightly different from medical and hazardous waste incineration facilities. It was found that the major contributors to the toxic PCDD/F concentrations were OCDD and 1234678-HpCDF contributing for 12.3%-23.0% and 15.0%-19.7% respectively. However, the largest contributor to I-TEQ was 23478-PeCDF and 33.1%-34.5% of I-TEQ was the presence of this congener. Correlation analysis showed that: 23478-PeCDF posed the best the correlation relationship with I-TEQ, R² 0.93-0.99. The most toxic 2378-TCDD only posed weak correlation with I-TEQ, R² 0.29-0.49. The correlation coefficient between the most abundant OCDD and I-TEQ was only 0.03-0.12. However, another abundant congener 1234678-HpCDF posed better correlation with I-TEQ, R² 0.62-0.87. Linear regression analysis showed that even I-TEQ fell into the concentration range of 5-6 orders of magnitudes, the linear relationship between 23478-PeCDF and I-TEQ was still excellent. The slopes of that lines, in different waste incineration facilities, were in the range of 1.16-1.40 and R² 0.94-0.97.